1. Field of the Invention
The invention relates to structural components made from at least two securely adhering layers A and B, one of which is made from a fibrous reinforcing support and a thermoplastic resin and the other of which is made of rubber, as well as to methods for the manufacture of such structural components.
2. Discussion of the Background
It is known that a single material cannot always have all of the characteristics expected of an object. For example, high strength, rigidity or hardness on the one hand, and good oscillation dampening, malleability or skid resistance on the other, are not compatible. If an item is intended to possess all of these characteristics, composites of several materials are used.
An obvious solution in this case is a composite of metal and rubber.
This combination, however, has two important disadvantages:
1. Metals have a high density, i.e. the structural components made therefrom are heavy.
2. Metal and rubber are not easily bonded and providing the metal with an adhesion enhancer is difficult.
Composites between caoutchouc and glass or aramide fibers are known (see W. Kleeman "Mischungen fuer die Elastverarbeitung," VEB, Deutscher Verlag fuer Grundstoffindustrie, Leipzig, 1982, Chapter 20, pp. 296 et seq.). However, these systems do not provide for the manufacture of rigid plates or other rigid elements of any desired shape. It is also known to treat glass fibers with gamma-aminopropyltrimethoxysilane and then to inclose them in thermosetting plastics, such as formaldehyde-resorcinol copolymers or polyurethanes. In the last step, a composite with caoutchouc is achieved, for example, with the use of vinylpyridine copolymers. Thermosetting plastics, once they have hardened, are no longer deformable. Yet, for many applications this restriction is unsatisfactory.
Carbon fiber reinforced thermoplastic resins are described, for example, in the book, Developments in Reinforced Plastics -4, Elsevier Applied Science Publishers, 1984, by Paul E. McMahon. It is recognized that the systems described there would meet the above-described requirements, if the reinforced thermoplastic resin was to engage in a solid bond with caoutchouc. Examination shows that this is not the case. The vulcanized caoutchouc can be pulled away from the surface of the thermoplastic resins with a small force, i.e. less than 0.7 N/mm in the case of a composite of carbon fibers, polyether ether ketone, and E-SBRcaoutchouc. Therefore, according to the prior art, it is not possible to manufacture structural components of (a) thermoplastic resin and reinforcing fibers and (b) caoutchouc in a simple manner.